1. Field of the Invention
The present invention relates to a slide fastener slider manufactured by molding a cantilevered pull-tab attaching lug on a slider body by die-casting using metal, then threading an attachment ring of a pull tab onto the pull-tab attaching lug from its free end and finally plastically deforming the pull-tab attaching lug by pressing. The invention relates also to a mold for die-casting such slider.
2. Description of the Related Art
In slide fastener sliders of the described type, it has been a common practice to provide a cantilevered pull-tab attaching lug on a front end of an upper wing of the slider body so as to leave a gap between its rear or free end and the upper wing, then to thread the attachment ring of the pull tab onto the pull-tab attaching lug via the gap and finally to plastically deform the pull-tab attaching lug by pressing to reduce the size of the gap to prevent accidental removal of the attached pull tab.
Japanese Utility Model Publication No. Hei 2-12889 discloses a die-casting mold for slide fastener slider, comprising an upper die of lateral-split type for molding the upper half part of the upper wing and the cantilevered pull-tab attaching lug, a lower die of lateral-split type for molding the exteriors of lower half part of the lower wing, a first slide core disposed between the upper and lower dies and longitudinally slidable to enter the slider body from its front end for molding the front part of the guide post and the interiors of a guide channel and of guide flanges, and a second slide core engageable with the first slide core and longitudinally slidable to enter the slider body from its rear end for molding the rear part of the guide post and exteriors of the guide channel and of the guide flanges.
According to the above-mentioned conventional slider, when the pull-tab attaching lug is pressed on its top surface to plastically deform its base after the pull tab is mounted onto the pull-tab attaching lug, a great pressing force is required so that the base would tend to be cracked or otherwise damaged. Besides, the slider body inevitably has parting lines on the longitudinal, central portions of the slider, including the pull-tab attaching lug, making the overall appearance of the slider body unsightly.
According to the above-mentioned conventional die-casting mold, since the upper and lower dies for molding the slider body are parted laterally in opposite directions, parting lines would occur longitudinally and centrally on and along the slider body itself and the pull-tab attaching lug as well, making the overall appearance of the slider unsightly. Further, with this conventional mold, it is difficult to manufacture such a slider that the pull-tab attaching lug can be plastically deformed easily by pressing.